Even when brain injury is so subtle that it can only be detected by an ultra-sensitive imaging test, the injury might predispose soldiers in combat to post-traumatic stress disorder, according to a University of Rochester Medical Center study. The research is important for physicians who are caring for troops in the years following deployment, as they try to untangle the symptom overlap between PTSD and mild traumatic brain injury (mild TBI) and provide the appropriate treatment. Until now, the nature of the interaction between TBI and PTSD was unclear. URMC researchers believe they are the first to find an association that can be demonstrated with advanced imaging techniques.